Valve assembly



8 w 49 v s 2 g M y 3 t o NH t mp1s v WW Wm m H u m i II h fi June 13, 1939. H. H. BIXLER VALVE ASSEMBLY Filed April 1, 1951 Patented June-13, 193a PATENT ornca VALVE ASSEMBLY- llarley H. Bixler, Schenectady, N.Y., assignor to General Electric Company, a corporation of New York Application April 1, 1937. Serial No. 134,3:0

9 Claims: (Cl. 277-60) My invention relates to valve assemblies for compressors, or, the like.

It is an object oi my inventionto provide a valve assembly for a compressor,or the like, which requires a minimum number of parts, which may be easily and economically manufactured and which is quiet and efficient in operation.

' It is another object, of my invention to provide a compressor, or the like, having. a cylinder pro-' ing in which Fig. l is a side elevation, partly in section, of a refrigerating machine including a compressor provided with a valve assembly embodying my invention; Fig. 2 is-a plan view, partly in section, on the line 2-2 of the compressor included in the refrigerating machine shown in Fig. 1; Fig. 3 is a sectional view, on the line 3-4 of the valveassembly included in the refrigerant compressor shown'in Fig.. 2; Fig. 4 is a fragmentary sectional view on the line 4-4 of a relief valve included in the valve assembly shownin Fig. 3; and Fig. 5 is an exploded perspective view of an end of the compressor cylinder and an inlet valve supporting member included in the valve assembly secured thereto, shown in Fig. 2.

Referring to the drawing, in Fig. 1 I have shown a refrigerating machine including a compressor H), which issecured to the top of a vertical electric driving motor II by a plurality of bolts 12,

thus forming a unitary structure. The compressor l0 and the driving motor H are mounted on a plurality of equally spaced-apart supporting springs l3 and are arranged in an hermetically sealed casing l4. This compressor I0 is of the Scotch yoke type and includes a piston 15 which reciprocates in, a longitudinal horizontal cylinder bore l6 formed in acylinder l1. The open end of the cylinder bore is adjacent the head of the piston I5 is closed by a valve assembly 18.

The valve assembly It includes a flat rectangular valve plate 19 made of steel, or the like, and constituting a head for the cylinder here It. The valve plate I! is provided with a relatively large inlet passage 20 extending therethrough and a series of relatively small discharge passages 2i extending therethrough. The discharge passages 2| are preferably arranged about the arc of a circle, as shown in Fig. 3. A thin, flat, rectangular inlet valve supporting member formed of spring steel or the like extends across the face of th valve plate l8 adjacent the cylinder l1. It will be noted that the end of the cylinder i1 is also of rectangular configuration and has the same peripheral dimensions as the inlet valve supporting member 22 and the valve plate IS. The inlet valve supporting member 22 is provided-with a centrally located punched aperture 23 which extends about the inner ends of the discharge passages 2|, thus aifording. free communication be- I tween the cylinder bore and the discharge pasof the circular aperture 23, and a slot 24a extends about the tongue. The surface of the valve plate I9 is, ground, or otherwise machined flat around the inner end of the inlet passage 20 thus forming a valve seat on which the enlarged end 25' of the inlet valve tongue 24 rests to close the inlet passage 20 during the operation of the compressor. An arcuate-shapedrecess 21 is formed in the end of the cylinder. l1 adjacent the cylinder bore I6 and extends about the end of the cylinder substantially 90 from a position adjacent the upper portion or top of the end of the cylinder 7 to a position adjacent the. side of the end of the cylinder. It 'will' be noted that the recess 21 has an inclined bottom wall 21a which is substantially in the plane of the end of the cylinder l1 at the top thereof and is somewhat below the plane of the end of the cylinder adjacent the side thereof. The recess 21 surrounds the inlet valve tongue 24, and the bottom wall 21a thereof serves as a supporting wall for the inlet valve tongue 24 when the latter is flexed to a position displaced from the valve seat to open the inlet passage 20. The inlet valve tongue 24 is supported substantiallythroughout its entire length when it is flexed to its open position due to the inclination of .the bottom wall 21a, which reduces stresses in the inlet valve tongue and minimizes vibration thereof and attendant breakage. During operation of the compressor, a thin film of lubricant accumulates in the recess 21 which further cushions opening movement of the inlet valve tongue 24 and minimizes traveling waves set up in the inlet valve tongues. The disposition of the recess 21 along the upper portion or top of the end of the cylinder i1 and adjacent the cylinder bore l8 preventsundue accumulation of lubricant therein and the tendency of the inlet valve tongue 24 to stick to the bottom wall 21a of the recess 21. Also, since the opening movement of the inlet valve tongue 24 is positively limited by the bottom wan 21 of the recess 21, its movement undermthe" action of an unloader actuating rod, hereinafter described, is

limited, as is the length of travel of the unloader -of the circle on the periphery of which the discharge passages 2| are located. The outer end of the rivet 30 is provided with an enlarged cylindrical head 32, and the inner end 33 thereof is peened over in a countersink 34 formed in the valve plate ii at the inner end 3| therein.

The exhaust valve and retainer structure, described above, is not my inv invention of Christian 8 nstrup, and is described and claimed in his copending application, Serial No. .068, filed June 11, 1935, now Patent No. 2,0 ,842, granted Oct. 12, ,93 and assigned to the General Electric Company, the assignee of my present invention.

The valve assembly ll also includes a rectangular muflie box 35, secured to the outer face of the valve plate I! by screws 34'. The screws 36 pass through registering holes in the muiiie box 35 and in the valve plate i9; they also pass through registering holes 21 formed in the inlet valve supporting member 22 adjacent the corners thereof. The inner ends of the screws 38 are secured in tapped holes formed in the cylinder II. The screws 36 thus serve to secure the valve assembly it, including the muiiie box 25, the valve plate is, and the inlet valve supporting member 22, on the open end of the cylinder H. The muiile box 35 is provided with an inlet recess 38 formed therein, one end of which registers with the inlet passage 2.. The munie box 25 is also provided with a discharge recess I! formed therein, which communicates with the outer ends of the discharge passages 2i.

The compressor I II is provided with an unloader cylinder 40 which is formed as an integral part of the casting of the compressor cylinder IT. The unloader cylinder 40 has a longitudinal cylindrical bore 4| formed therein, parallel to the compressor cylinder bore IS, in which an unloader piston 42 is arranged. A U-shaped operating rod 43 is secured at one end to a disk 44 rigidly mounted in the unloader piston 42, and the opposite end 45 of the operating rod '42 passes through a guiding bore 46 formed in the muflie box 35 and bears against the enlarged end 25 of the inlet valve tongue 24, thus opening the inlet passage 20. The operating rod 43 and unloader piston 42 are biased, to the position illustrated in Fig. 2, by a helical compression spring 41 mounted between the disk 44 and a retaining plate 48, which is secured to the muiiie box 35 by two of the screws 36. By this arrangement the compressor III is unloaded in starting, as the inlet valve tongue 24 is held open until the compressor attains a predetermined per cent of its normal running speed. The compressor is loaded at that speed by oil pressure actuating the piston 42 to release the inlet valve tongue 24.

The compressor unloader structure described above forms no part of my present invent on of the hole I tion, but is the but is described and claimed application, Serial No. 1935, now Patent No. 1937, and assignedto the General Electric Company..the assignee of my present invention.

As shown in Figs. 3 and 4, a relief valve passage 49 is provided in the valve plate It within the periphery of the circular opening 23 formed in the inlet valve supporting member 22. The relief valve w e 49 communicates with. a larger e ill formed in the muiiie box 35, which in turn communicates with a hole ll formed in the retaining plate 48. The relief passage 49 is normally closed by a disk-shaped relief valve element [2 having a narrow annular in my copending 1337, filed January 1 seating portion 520. The relief valve element l2 is'resiliently retained. in position across the end of the relief passage 49 by a helical com-. pression spring I2 held under compression between a stud 54 having an enlarged rounded end II bearing against the back of the relief valve element 2 and an integral tab 56 formed on the-retaining plate 48 and extending across the hole 5| formed therein. The integral tab It is bendable with respect to the retaining plate 48 in order to adjust the tension upon the helical compression spring 52'. The integral tab 56 directly engages one end of the helical compression'spring I and the other endof the helical compression spring istightly fitted on the body portion of the stud 54 in engagement with the back of theenlarged end of the stud 54. The

2,102,403, granted Dec.

compression spring 53 normally biases the relief valve element I2 to the closed position illustrated in Fig. 4 and is made of such strength and so adjusted by bending the integral tab 58 that when the pressure within the compressor cylinder bore l6 extends a predetermined value considerably above the normal discharge pressure. the relief valve element 52 will be forced backward away from the end of the relief passage 4! and part of the compressed fluid contained in the cylinder bore I will be passed therefrom through the relief passage 49 and through the relief valve mechanism into the interior of the casing l4 until the pressure within the cylinder bore ll falls to a safe value. The pressure in the cylinder bore I! may rise to the predetermined abnormal value referred to because of an climction in the condenser, failure of the discharge valve to open, or for some other similar reason. The'compressor and condenser are thus protected from such abnormal pressures.

One side of the relief valve element 52 is in direct communication with the interior of the easing l4, which contains low pressure gaseous refrigerant, and constitutes azone of relatively low pressure. It is particularly advantageous in such case to arrange the opposite side of the relief valve element 52 in direct communication with the interior of the cylinder bore It as shown, rather than with the interior of the discharge recess 39, for example. This will be more readily understood from a consideration of the cycle of pressures to which the relief valve element 52 is subjected, when arranged as illustrated in the drawing. The compressor ll of the refrigerating machine ordinarily operates only about 25% of the time, when subjected to normal load. During such period of operation, the pressure of the gaseous refrigerant compressed in the cylinder bore l6 exceeds the pressure of the gaseous refrigerant in the casing l4 by a substantial amount for only about half of each compression stroke. As

aioasvo a consequence, there is a pressure exertedon the inner face of the valve element-ll tending to un-i seat the same during only about one-sixteenthof the total elapsed time in which the machine-is in use. The. strain onthe compressionspring It is thus minimized and its life. consequently increased. The high pressure in the cylinder bore i6 is applied to the relief valve element I! in alternation with a low pressure in the cylinder bore It. during the suction stroke of the piston ll therein, so that the high-pressure or unseating pressure is nevercontinuously applied during the normal operation of the machine. This is advantageoiu since I have foundthat if high pressure gas, such as that contained in the discharge recess 39, is continuously applied to the inlet side of .the relief valve' element It, the relief valve element may be gradually moved from its seat a slight distance, so that it in effect floats on a gas film and permits a continous leakage of gas. On the other hand, whenthe relief valve element 52 is arranged as shown in the drawing, so that. it is drawn against its seat on each suction stroke of the piston II, the seating of the valve element is maintained in its proper condition and leakage is prevented. I prefer to employ a relatively narrow annular seating portion 2a on the relief valve element 82 to minimize sticking of the valve on its seat. Gum-like oil, rust or other foreign matter may collect on the seating portion of the relief valve element, but if the seating area is i made small, suchforeign matter: wiilnot prevent the proper opening of the relief valve element when the predetermined pressure conditions prevail.

In the operation of the refrigerating machine, shown in Fig. 1, when the electric driving motor I I is started, lubricant is supplied under pressure by a pump (not shown) from the body of lubricant 51 contained in the lower portion of the hermetically sealed casing it to the lbore ll of the unloader cylinder 40. when the compressor reaches about 80 per cent of full speed, the pressure of the accumulated lubricant within the unto the inlet passage Ill formed in the valve plate l9. When the reciprocating piston I5 is retracted within the compressor cylinder bore ii, the pressure therein is decreased and the resilient inlet valve tongue 24 is consequently flexed inwardly, under the pressure of the gas in the inlet passage 20, thus opening the inner end of the inlet passage and allowing the compressor cylinder bore it to be filled with gaseous refrigerant. At the same time, the discharge valve element II is substantially flattened against the valve plate is by the pressure 01' the gas in the discharge recess 39 formed in the muilie box", thus closing the discharge passages 2i. When the reciprocating piston moves toward the valve assembly i8 on the compression stroke,- the pressure of gaseous refrigerant contained in the come pressor cylinder bore l6 risesand the enlarged end 25 on the resilient inlet valve tongue 24 is fiexed back into engagement with the valve seat to closethe inlet passage 2!, and the piston I! then compresses the gas in the cylinder. When the pressure of the gaseous refrigerant 001m pressed ,in the compressor cylinder bare it reaches .a predetermined value was respect to the pressure of the gaseous refrigerant in the discharge recess II, the discharge valve element It is flexed outwardly against the retainer 2! by the differential in pressure thus created, opening thedischarge passages II. The compressed gaseous refrigerant then passes from the compressor cylinder bore it, through the discharge passages ll, into the discharge recess 3! formed in the mono box II, from whichit passes through a conduit 00 to a discharge muilier 8|.

The compressed gaseous refrigerant flows from the discharge muiiier ll through a conduit 02, to the upper end of a naturaldraft air-cooled condenser ".I where it is liquefied by the transferof heat therefrom to the cooling air circulating. over the surfaces of the condenser. The refrigerant iiquefledin-the condenser it flows therefrom through a conduit 64, passes through a fiowcontrolling float valve 85, and is supplied through a liquidline it too flooded type evaporator 61. 'Iheevaporator 61 is supported on the lower side "of a removable top wall SI of a refrigerator cabinet, or the like, provided with a cooling compartment in which the exaporator 61 is located. The l quid refrigerant contained in the evaporator 81 is vaporized by the absorption of 'heat from the compartment in which it is located andthe vaporized refrigerant is collected above the level of the liquid refrigerant in a header. 6! of the evaporator ll. The vaporized refrigerant collected in the header is is then returned through a suction conduit 10, which is connected to the header it, above the normallevel of the liquid refrigerant therein, to the casing ll above the level ofthe body of lubricant therein. The cycle above described is continuously repeated until the compartment in which the evaporator 61 is located is cooled to the desiredtemperature.

While I have shown a particular embodiment of my invention in connectionwitha compression type refrigerating machine, Ido not desire my invention to be limited to the particular construction shown and described, and I intend in the appended claims to cover all modifications within the spirit and scope of my invention.

.What I claim as new and desire to secure by Letters Patent of the United States is:

l. A valve assembly for a compressor, or the like, comprising a valve plate having an inlet passage and a discharge passage extending therethrough, said valve plate having a valve seat thereon extending about one end of said inlet passage, an inlet valve supporting member extending across one face of said valve plate and having an aperture therein extending about one end of said discharge passage, and an integral flexible: inlet valve tongue formed on said valve supporting member, said inlet valve tongue extending alongthe margin of said aperture and cooperating with said valve seat to close said' inlet valve supporting member and extending along the periphery of said aperture, and means including an enlarged end formed on said inlet valve tongue and extending into said notch and cooperating with said valve seat to close said inlet passage.

3. A valve assembly for a compressor, or the like, comprising a valve plate having an inlet passage extending therethrough and a series of discharge passages extending therethrough and arranged on the periphery of a circle, said valve plate having a valve seat thereonextending about one end of said inlet passage, an inlet valve supporting member extending across one face of said valve plate and having a circular aperture therein extending about the ends'of said series of discharge passages, and an integral flexible inlet valve tongue formed on said inlet valve supporting member, said inlet valve tongue extending along the periphery of said aperture and cooperating with said valve seat to close said inlet passage.

4. A valve assembly for a compressor or the like comprising a valve plate having an inlet passage, and a discharge passage extending therethrough, said valve plate having a valve seat thereon extending about the inner end of said inlet passage, an inlet valve supporting member extending across the face of said valveplate and having an aperture therein extending about one end of said discharge passage, an integral flexible inlet valve tongue formed on said inlet valve supporting member and extending along the margin of said aperture, said inlet valve tongue cooperating with said' valve seat to close said inlet passage and flexing to a position displaced from said valve seat to open said inlet passage,

means for supporting said inlet valve tongue throughout substantially the entire length thereof when said inlet valve tongue is flexed to its open position, and means for securing said valve plate and said inlet valve supporting member together.

5. A valve assembly for a compressor or the like comprising a valve plate having an inlet passage and a series of discharge passages arranged on the periphery of a circle extending therethrough, said inlet passage and said .discharge passages communicating with said bore, said valve plate having a valve seat thereon extending about the inner end of said inlet passage, an inlet valve supporting member extending across the face of said valve plate having a circular aperture therein extending about the inner ends of said series of discharge passages, an integral flexible inlet vave tongue formed on said inlet valve supporting member and extending along the periphcry of said aperture, said inlet valve tongue cooperating with said valve seat to close said inlet passage and flexing to a position displaced from sad valve seat to open said inlet passage, means including a recess for supporting said inlet valve tonguethroughout substantially the entire length thereof when said inlet valve tongue is flexed to its open position, and means for securing said valve plate and said inlet valve supporting member together.

6. A valve assembly for a compressor or the like comprising a valve plate having an inlet passage and a discharge passage extending therethrough, said valve plate having a valve seat thereon extending about the inner end of said inlet passage, an inlet valve supporting member extending across the face of said valve plate having an aperture therein extending about one end of said discharge passage, an integral flexible inlet valve tongue formed on said inlet valve supporting member and extending along the margin of said aperture, said inlet valve tongue cooperating with said valve seat to close said inlet passage and flexing to a position displaced from said valve seat to open said inlet passage, means including a recess'for supporting said 'inlet valve tongue throughout substantially the entire length thereof when said inlet valve tongue is flexed to its open position, and means for securing said valve plate and said inlet valve supporting member together.

7. A valve assembly for a compressor, or the like, comprising a valve plate having an inlet passage and a discharge passage extending therethrough, said valve plate also having a relief passage extending therethrough, said valve plate having a valve seat thereonextending about one end of said inlet passage, an inlet valve supporting member extending across the face of said valve plate and having an aperture therein extending about one end of said discharge passage and of said relief passage, anintegral flexible inlet valve tongue formed on said inlet valve supporting member and cooperating with said valve seat to close said inlet passage, a relief valve element arranged to close one end of said relief passage, means including a helical compression spring for biasing said relief valve element to close said relief passage, and means including a plate-having a bendable tab member for adjusting the tension of saidcompression spring.

8. A valve assembly for a compressor, or the like, comprising a valve plate having an inlet passage and a relief passage extending therethrough and also having a series of discharge passages arranged on' the periphery of a circle extending therethrough, said relief passage being positioned outside the periphery of said circle, said valve plate having a valve seat thereon extending about one end of said inlet passage, an inlet valve supporting member extending across one face of said valve plate and having a circular aperture therein extending about the ends of said series of discharge passages and said relief passage, an integral flexible inlet valve tongue formed on said inlet valve supporting member and extending along the periphery of said aperture, said inlet valve tongue cooperating with said valve seat to close said inlet passage, -a relief Valve element extending across one end of said relief passage, means including a helical compressionspring for biasing said relief valve element to close said relief passage, and means including a plate having a bendable tab member for adjusting the tension of said compression spring.

9. A valve assembly for a compressor, or the like, comprising a valve plate having a relief passage therein, a mufiie box mounted on said valve plate and having a passage therein communicating with said relief passage, a valve element arranged to close said relief passage, 'means including a-helical compression spring mounted in said passage in said muille box for biasing said valve element to close said relief passage, and means including a plate mounted on said muille box having a bendable tab arranged over the end of said passage in said mume box and engaging the end of said compression spring for adjusting the tension of said compression spring.

HARLEY H. BIXLER. 

